import java.util.Scanner;

public class N {
  /*  public static int func1(int n){
        int ret =1;
        for (int i = 1; i <= n; i++) {
            ret *= i;
        }
        return ret;
    }*/
    public static int func1(int num){
       // int ret = 1;
        if(num == 1){
            return 1;
        }

      return num*func1(num-1);
  }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个数: ");
        int num = sc.nextInt();
            int sum=func1(5);
        System.out.println(sum);
    }
}
